03 sorento ex 3.5 with 90,000 miles
Normal accelerating driving and it felt like i took my foot off the gas pedal and then replied it. At first i thought maybe that's what i did. Then i came to a red light, light changed green, hit the gas, and it happened at about 15mph again and then it kicked back in a sec later. I approached the next red light and it stalled out and then it started right back up. These symptoms have just started tonight but there has been a slight erratic idle for a few months and i figured maybe wires need to be changed (spark plugs i changed already). Just gas/throttle cuts off for like a second. Lights remain on when this happens. I hope this isnt the tranny.. no slipping. Possibly ignition?? I searched before posting this question but it seems like a tough one. No check engine light either.
Any clues?? thanks

hmmm... didnt think of that but most certainly possible.. I really like the fact that i could get to that pump though the back seat. I never had that privilege on any of my other cars.. I wish i would get some kind of light on to pull codes.. gonna look at it today but im leaning towards changing the wires. I figure i need to start with the basics first. I will also check comp and fuel pressure while im at it and have everything apart. Sux i gotta pull this upper intake i think to change these wires but ahhh well.. what are ya gonna do.. I believe whats happening is an engine surge which might indicate lack of spark. We shall see..

I would have someone test your TPS first.
I just did a major parts replacement on my 03. It has 117,000 miles. While I had the surge tank off I replaced the Valve Cover gaskets and spark plug tube gaskets. Also replace the 2 heater hoses in the back. Make sure you get the wires in the right order in the little rack behind the engine. Mark, Mark, Mark, everything. If they get crossed you can get a misfire. Also be VERY CAREFULL when putting the surge tank or the valve covers back on. The fuel injector harness is right there and very brittle. (Don't ask how I know). I found that locally no one had the gasket that goes between the intake manifold and the tank. Order ahead. Rock Auto has alot of the parts you need. I bought a set from them that looked identical to OEM for about 30-40 $$. I also did the timing belt and all that goes with it. When were the plugs changed last? Might as well do them also if it has been 40,000 or more miles. Water pump done? You my friend are at that mileage for all kinds of preventative maintenance that should be done. You can wait but I don't know how fast you rack up the mileage. If you do the work yourself you can save alot of money.

hey thanks for that info.. I changed the plugs about 6 months ago and the wonderful fun to replace hoses in the back, i did about 2 months ago. That little 't' broke and i had antifreeze all over the place at a mcdonalds drive through. I replaced that 't' and all of the hoses with out removing the upper intake and needless to say, my hands were a mess after that uhh.. maybe i will do the water pump too while im at it sure. Its not a daily drive, just a errands car after work and weekends because i have my work truck that i drive every day. Nobody has parts ur right lol. Do u think i should go oem for the wires? They should carry all my gaskets too right?? Hope so, otherwise rock auto here i come.. Thanks for the heads up on that harness

hey thanks for that info.. I changed the plugs about 6 months ago and the wonderful fun to replace hoses in the back, i did about 2 months ago. That little 't' broke and i had antifreeze all over the place at a mcdonalds drive through. I replaced that 't' and all of the hoses with out removing the upper intake and needless to say, my hands were a mess after that uhh.. maybe i will do the water pump too while im at it sure. Its not a daily drive, just a errands car after work and weekends because i have my work truck that i drive every day. Nobody has parts ur right lol. Do u think i should go oem for the wires? They should carry all my gaskets too right?? Hope so, otherwise rock auto here i come.. Thanks for the heads up on that harness

Unless I missed it you did not say it till now. HAVE YOU EVER changed the fuel filter in 90K? As tht might be part and parcel of why Aref is correct and might be onto something with pump idea. KISS, (keep it simple stupid) first as the lack of a filter in 90K could mean it is just clogged FINALLY from the sludge since 2003 or it has taken the pump with it for that issue now. Changing a $45 filter twice in 90K might have saved you $300 now. Depends on how you do the pump too you might even need to BUY a filter to do it still. As the SENDER PUMP ASSY comes five ways still I hope.

I never heard of a car not having a fuel filter but the kia parts guy said that there is no filter when i was in there buying maintenance parts about 6 months ago.. I thought that was strange and most likely wrong but just left it as is. Im already into it with the car and i wanted to change the wires anyway so its not a problem. I broke everything down even the timing cover is off. I didn't remove the belt at all and im aware of the special procedure or removal and replacement. However, this belt looks new or at least to me it does. Would you see wear or cracks on a 90k belt or might it just stretch out a bit. Manually, i am able to spin the water-pump with my hand with the belt on but it looks nice and tight/snug over the sprockets. I bought the car at 80k from a dealer but that's the same dealer i bought from 6 months ago and now they are out of business. I would have called and checked to see if it was done already..
I never loosened the crankshaft bolt before hand and now unsure of how to get this off.. sux... correction: crankshaft pully tool will come in handy lol

I never heard of a car not having a fuel filter but the kia parts guy said that there is no filter when i was in there buying maintenance parts about 6 months ago.. I thought that was strange and most likely wrong but just left it as is. Im already into it with the car and i wanted to change the wires anyway so its not a problem. I broke everything down even the timing cover is off. I didn't remove the belt at all and im aware of the special procedure or removal and replacement. However, this belt looks new or at least to me it does. Would you see wear or cracks on a 90k belt or might it just stretch out a bit. Manually, i am able to spin the water-pump with my hand with the belt on but it looks nice and tight/snug over the sprockets. I bought the car at 80k from a dealer but that's the same dealer i bought from 6 months ago and now they are out of business. I would have called and checked to see if it was done already..
I never loosened the crankshaft bolt before hand and now unsure of how to get this off.. sux... correction: crankshaft pully tool will come in handy lol

LOLOL then you have a "SPECIAL" one. And that parts guy rides the Short Bus to work. My old 2004 SORENTO LX 3.5L V6 2WD 4spd auto had one. In the tank on the WHOLE (pump/filter/sender/cage) plug and play unit. Like you said it is in the back seat under the panel and under the floor.

SENDER UNIT 31150-3E300 $43.47 warranty at 46,235 8/13/2008 due to KNOWN (TS gauge goofiness. And I had it doing just that then.
FUEL FILTER 31911-3E200 $43.05/$74.73 installed by dealer at 46,235 8/13/2008 had done while doing the sender.
COMPLETE PUMP ASSY 31150-3E200 warranty at 46,362 8/21/2008 due to messed up filter install. Messed up the NEW o-rings on install, pump burnt out in two days from running dry and wet and dry and wet. Stalling and looseing prime too on way home. Called and told to drive it as I filled tank on way home and it might have a "AIR POCKET" and would clear up in a day. TOWED BACK IN DEAD. LOLOLOLOL

I never heard of a car not having a fuel filter but the kia parts guy said that there is no filter when i was in there buying maintenance parts about 6 months ago.. I thought that was strange and most likely wrong but just left it as is. Im already into it with the car and i wanted to change the wires anyway so its not a problem. I broke everything down even the timing cover is off. I didn't remove the belt at all and im aware of the special procedure or removal and replacement. However, this belt looks new or at least to me it does.If the belt has 90k on it replace it no matter what it looks like.
Would you see wear or cracks on a 90k belt or might it just stretch out a bit. Manually, i am able to spin the water-pump with my hand with the belt on but it looks nice and tight/snug over the sprockets. If you measured the hydraulic tensioner you will most likely find it is sticking out farther than the specs call for. It means the belt is stretched. Mine was 2X as far out as it should have been. I bought the car at 80k from a dealer but that's the same dealer i bought from 6 months ago and now they are out of business. I would have called and checked to see if it was done already..
I never loosened the crankshaft bolt before hand and now unsure of how to get this off.. sux... correction: crankshaft pully tool will come in handy lol

parts i will change,
spark plug wires
water pump
timing belt, tensioner
tensioner pulley
idler pulley,
thermostat
coil packs
upper You don't need the upper. It goes between the top half of the surge tank. lower intake gasket, tb gasket
some vacuum lines on top of intake
apparently now a fuel filter
drive belts
coolant hoses

Be prepared to purchase the drive belt idler and the P/S idler. I have 117 k on mine and they were worn. Any oil seepage from the valve covers.

I modyfied a few of your pictures with thing I found when I did my TB and covers.

You will absolutely find it easier to remove the cowling to do the wires. It will all come out including the wipers. Your hand and sanity will thank you when you are finished. Remember to label everything that has to do with the ignition. The diagrams from KiaTech can be confusing. The are not consistant with their descriptions. Hope this helps.

thank you very much for that useful info. It def helps especially since this is my first time with the sorento. I def do notice lots of parts are brittle taking apart. I already broke a tiny coolant tube that sticks out of the top of the radiator going to i think the intake. I'm gonna have to try tapping in a brass fitting i think. Also broke the ac wiring harness. Maybe it was already broke but just from giving it a small pull, it split in half. Its just one wire so i should be able to just bi-pass that harness and hard wire right?
Thanks again